The invention relates to a sewing machine having a needle bar mounted in a swinging frame.
The patent specification DEOS 1680830 U.S. Pat. No. 3,460,494 discloses a swing drive of a needle bar frame which is not fully positive, in that a spring biassed cam follower is pressed continuously against the periphery of a cam, which imparts a swinging movement to the needle bar frame. Although this design is simple in terms of parts, it does not allow such sewing machines to be used in high-speed machinery, for example for sewing or closing sacks, since this would place much more exacting requirements on such a needle bar swinging drive.